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United States Patent | 5,540,411 |
Strickland | July 30, 1996 |
A plastic liner for protecting concrete manhole interior surfaces from corrosion wherein the liner includes provisions for creating a strong mechanical lock between the liner and the interior surfaces. A side of the liner which includes the provisions has a plurality of raised hollow projections with spaced sections. The mechanical lock is created when concrete is poured against the side of the liner with the projections. The concrete at least partially enters the hollow portions and fills spaces between the projection sections. The projections also intersect to enhance the mechanical lock by preventing bulging. Liner sections cover essentially all of the manhole interior surfaces. Forming a liner section by rotationally molding the plastic and cutting gaps into the projections is also disclosed.
Inventors: | Strickland; James K. (Jacksonville, FL) |
Assignee: | Strickland Industries, Inc. (Jacksonville, FL) |
Appl. No.: | 377359 |
Filed: | January 24, 1995 |
Current U.S. Class: | 249/145; 249/146; 249/150; 249/151; 249/177; 249/184 |
Intern'l Class: | B28B 007/06; B28B 007/28 |
Field of Search: | 249/142,145,146,147,150,151,177,183,184,186 425/577,DIG. 44 |
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Foreign Patent Documents | |||
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